Setts



(No-Model.)

J. F. WILKINSON. BICYCLE CRANK PEDAL.

No. 590,557. Patented Sept. 21, 1897.

INYENTURI NITED STATES PATENT FFICE,

JOHN F. \VILKINSON, OF PEPPERELL, MASSACHUSETTS, ASSIGNOR, BY DIRECT ANDMESNE ASSIGNMENTS, O-F FIVE-EIGHTHS TO RUTH BROlVN, OF NEIV IPSYVIOH,NEW HAMPSHIRE, AND R. G. DAVIS, OF BOSTON, MASSACHU- SETTS.

BICYCLE-CRANK PEDAL.

SPECIFIGATIGN forming part of Letters Patent No. 59 0,557, datedSeptember 21, 1897.

Application filed June 1, 1396. Serial No. 593,710. (No model.)

To all whom it may concern:-

Be it known that I, JOHN F. WILKINSON, of

Pepperell, in the county of Middlesex and State of Massachusetts, haveinvented certain new and useful Improvements in Bicycle- Orank Pedals,of which the following is a specification.

The object of this invention is to provide a bicycle-crank with a pedalor foot-piece which during the downward or effective stroke will havethe time of its effective operation increased, said pedal being providedwith means which will automatically elevate its front portion to avoidexcessive motion of the riders ankle.

' To these ends the invention consists in the construction andcombination of parts, substantially as hereinafter described andclaimed. V

In the drawings which accompany and form part of this specification,Figure 1 represents an elevation of a bicycle-crank having its wrist-pinprovided with a pedal or foot-piece of my improved construction, theposition of the parts being that which they will occupy when thedownstroke is to be commenced, and the clotted-line position indicatingthe lowest portion of the downstroke. Fig. 2 represents a plan view ofthe pedal and a portion of the crank-arm. Fig. 3 represents a detailsection on the line 3 3 of Fig. 2. Fig. t represents a'perspective Viewof one form of attachment to the pedal, hereinafter described. Fig. 5represents a similar view of another form of attachment.

In the drawings, a represents the crankarm, having a wrist-pin b, whichis fitted to the sleeve 0 of the foot-piece or pedal. The wrist-pinextends through the pedal near 40 one end thereof, instead of at themiddle, as

is customary, this resulting in a tendency of the forward end of thepedal when at the commencement of the downstroke to descend or rotate onthe wrist-pin. This tendency is p prevented,.however, by a clutchmechanism consisting of the cam-surfaces e on the wristpin, betweenwhich and the inner periphery of a cup f, carried by the sleeve 0, arefitted the balls or cylindrical rollers g.- This particular form ofclutch is not a part of my invention, and I may substitute therefor anyother preferred form of clutch.

Attached to the front plate h of the pedal is anarm i, which extendsbackward under the sleeve 0 and then up to a position above the upperedge of the rear plate of the pedal, said arm presenting at this point atread-surface 2", that is elevated above the rear end of the pedal. Thisarm may consist of a piece of steel wire bent to the form as indicatedin Fig. 4 and having its ends passed through holes in the plate It andsecured thereto by suitable nuts, or it may consist of a piece of sheetmetal bent substantially as shown in Fig. 5 and'suitably bolted to thefront plate h of the pedal.

In using when the crank is moved to an upright position and itswrist-pin is in the position of what would originally be the deadcenterthe front plate h is in advance of this point, and pressure thereonimmediately imparts an effective force tending to rotate the crank, thisbeing due to the clutch mechan ism above described, which would preventany rearward oscillation of the pedal on the wrist-pin. At the momentwhen the rider would begin to exert downward pressure it is firstimparted to the tread-surface i, which immediately throws upward thefront plate h of the pedal to a position where the foot can accommodateitself at once to the proper position to acquire the necessary force.IVithout this arm 2' the foot in order to exert pressure upon the frontplate h would have to be bent at an angle sufficiently to carry the ballof the foot over upon said front plate.

WVhen the crank is in its lower position, as indicated by the dottedlines in Fig. 1, the front plate of the pedal, being in advance of thewrist-pin and held against downward rotation thereon, permits aneffective pressure being exerted until said front plate is in a verticalline beneath the axis rotation of the crank. In this position the arm '5performs the same function as above stated in that it tends to keep thefront plate elevated or to elevate it in case pressure of the foot hasbeen momentarily relieved.

in one direction about the Wrist-pin, and an elastic arm attached to thefront portion of the pedal, and extending to the rear of the wrist-pin,and above the plane of the rear portion of the pedal, the said Wrist-pinextendingth rough the pedal near the rear thereof, and the clutch beingadapted to grip at any point of rotation.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing Witnesses, this 23d day of May, A. D. 1896.

JOHN F. XVILKINSON. \Vitnesses:

(J. F. BROWN, A. D. HARRISON.

